Sealed bearings



Dec. l0, 1963 f KANJI OGURA 3,113,314

I SEALED BEARINGS Filed Dec. 18, 1961 //v VEN TQQ United States Patentce lll'iili Patented Dec. 10, 1963 3,113,814 SEALED BEARINGS Kanji@gni-a, Minamku, Osaka, Japan, assignor to Koyo Seiko Company, Ltd.,Osaka, Japan, a corporation of Japan Filed Dec. 18, 1961, Ser. No.159,843 Claims priority, appiication Japan Dec. 20, 1960 5 Claims. (Cl.30S-187.2)

This invention relates to sealed bearings.

Efforts have been made heretofore to eifect a labyrinth between an edgeof a bearing seal and a groove of a rolling inner bearing race in greasetight sealed bearings. However, in some forms, it is very difficult to`form a groove in the inner race or it is difficult to maintain aprecise gap or spacing between the inner race and the adjacent edge ofthe seal. In such cases, the frictional contact between the adjacentedge of the seal and a side of the groove in the inner race is apt todamage the seal and destroy the proper sealing eilect.

In case that edge of seal against inner race is made of metal, muchifrictional resistance arises, which not only obstructs the high speedrotation, but causes noise and heat by contact with inner race. Thisincreases the seals loss rate.

lf the seal is made of the usual elastic material and is provided withtongue-shaped edge inserted into a groove of the inner race, to avoidthe above mentioned disadvantage, fluid pressure arising from eccentricmotion of the enclosed grease presses the tongue-shaped edge of theelastic seal to one side of the groove with progressively increasingpressure as the speed of rotation of the roller members increases. Thisspoils the labyrinth effect which may have been produced by the elastictongue-Shaped edge and groove. Furthermore, when the elastictongue-shaped edge moves in the groove, axial displacement of the outerrace relative to the inner race which sometimes occurs during rotation,pushes grease off of some of the working parts. In worst cases, greaseis forced outside the bearing and is then drawn in again aftercontacting dirt and dust. Of course this defect of the seal being forcedto one side of the groove into contact with the groove surface bypressure can be eliminated by making the seal of metal. However, it isexceedingly dicult to assemble metal seals precisely in proper positionin the bearing, and such metal seals are often found to have the radialinner edge located against or adjacent a cylindrical edge surfaceportion of the inner race rather than in the groove of the inner race,so that an L-shaped gap occurs therebetween. Therefore, in order to tryto attain a good labyrinth eifect, seals having an elastic inner edgeinserted lightly into the groove, rather than metal seal, are usuallyemployed, but this, as stated above, does not maintain a true labyrintheffect because of distortion of the elastic edge into contact with aside of the groove by the grease pressure.

An object of the present invention, therefore, is the provision of novelresilient seal device for grease sealed ball bearings and the likewherein the seal is maintained out of contact with the inner race andforms a labyrinth between the radial inner edge of the seal and thegroove of the inner race.

Another object of the present invention is the provision of a novelsealed ball bearing assembly of the type described in the next precedingparagraph, wherein the labyrinth eifect is maintained regardless of huidpressure and wherein friction loss is reduced to a minimum.

Other objects, advantages and capabilities of the present invention willbecome apparent from the following detailed description, taken inconjunction with the drawing. The attached drawing is a view in centralradial section through a sealed bearing illustrating the invention.

Referring to the drawing illustrating a preferred exemplary embodimentof the present invention, there is illustrated a ball bearing assemblywhich includes an annular outer race A, an annular inner race Bconcentrically and radially aligned with the outer race A, and a rollingelement such as ball bearing C disposed in an annular concave race inthe adjacent surface of the inner yand outer race A, B, it beingunderstood that a series of such balls are located in circumferentiallyspaced relation by suitable separator or cage D. The seal of the presentinvention comprises `a seal body S having a relatively rigid center coreformed by a metal ring t3 having a hook-shaped flange 1 at its radiallyoutwardly disposed end extending toward the race-ways and a slightlyinclined ange 2 at its radial inwardly disposed edge. The center ring 3is covered by a rubber or similar plastic body R shaped to form `anelastic, bead like projection 4 extending into suitable stop groove 7 inthe outer race A and a forked seal formation along the inner edge of theseal having a radially inwardly extending elastic lip 5 adapted toproject loosely into a V-shaped groove 8 in the outer diameter surfaceof the inner race B adjacent the end of the inner race, and tongueformation 6 extending axially inwardly of the bearing in proximity tothe outer cylindrical surface of the inner race B. The seal is sodimensioned that the radical outer body projection 4 fits snugly intothe stop groove 7 of the outer race A to x the position of the sealrelative to the bearing assembly, while the radially inwardly projectinglip 5 and the tongue formation 6 extend close but lie slightly out ofContact with the adjacent portions of the inner race B. The lip `5projecting into the V-shaped groove 8 forms the labyrinth, while thetongue formation 6, which has 'a substantially triangular proile and anaxially inwardly directed apex, diverts the direction of flow of Ithegrease inwardly toward the zone occupied by the balls, as indicated bythe broken line arrows, to prevent grease flowing directly toward thegroove 8 and the lip 5 disposed therein.

By reason of the action of the tongue formation 6 in guiding the greaseflow axially inwardly toward the zone of the ball, it shields theelastic lip 5 from direct flow of grease and the position of thelabyrinth-forming lip 5 of the groove 8 is always maintained to preservethe desired labyrinth effect regardless of the uid pressure. Due to therelatively rigid center ring 3 which forms the center core of the sealbody S, the inclined ilange 2 of the ring 3 forms a base for the tongueformation 6 and desired gap between lip 5 and groove S, this can bereadily accomplished by further bending of the flange 2 with a suitabletool.

It will be appreciated that the labyrinth eifect provided `by lip 5 andgroove is extended along the region where the tongue formation 6 and theouter cylindrical portion of the inner race B are close to each other.With such an extended labyrinth effect, the grease will not be drawn inor forced out of the bearing even under high speed yrotation conditionsand thus wear and damage to bearings due to friction is held to ayminimum and foreign matter is effectively excluded from entering thebearing. The hook-shaped character of the seal body at the radiallyVouter edge thereof `adapted to be seated in a stop groove of thecharacter shown permits the central portion of the sealing body to bedisposed substantially ushed with the end surface of the inner and outerrace, thus increasr ing the grease accommodating capacity of thebearing.

It Will be appreciated that the present invention is applicable toroller bearings of many different types, and is not limited to ballbearings only.

While only one preferred Vembodiment of the invention has beenparticularly shown and described, it is apparent that othermodifications may bemade in the invention without departing from thespirit and scope thereof, and it is desired, therefore, that only suchlimitations shall be placed thereon as are set forth in the appendedclaims.

l claim:

1. ln an anti-friction bearing assembly including spaced relativelyrotatable inner and outer race ring members disposed in concentricrelation and held against relative -aXial movement, Asaid inner ringmember having a cylindrical cuter surface having an annular outwardlyopening sealing groove therein, a unitary seal carried by said outerring member cooperating with said ring members to detine one end of asealed grease chamber between said ring members, said seal comprising anouter rubber-like elastic body having -a rigid metallic reinforcing ringembedded therein with the elastic body in wholly covering relation tosaid metallic ring, said elastic body having a forked inner edgeformation including a radially inwardly projecting lip portion and anaxially projecting tongue por- Vtion, said lip portion conformingsubstantially to the cross-section of said sealing groove and extendinginto the same out of contact with the surface thereof to form alabyrinth passage therewith, said tongue portion being disposed inspaced concentric overlying relation to an annular portion of saidcylindrical outer surface of said inner ring member immediatelyadjoining said sealing groove inwardly of said Vgrease chamber, and saidseal being constructed to maintain said lip portion and said tongueportion in slightly spaced relation to said sealing groove surfaces andthe adjacent `annular surface portions of said inner ring member overthe range of fluid pressures encountered in said bearing assembly duringuse.

2. In an anti-friction bearing assembly including spaced relativelyrotatable inner `and outer race ring members disposed in concentricrelation and held against relative axial movement, said outer ringmember having a radially inwardly opening stop groove adjacent one endthereof and s-aid inner ring including a cylindrical outer surfacehaving an vannular outwardly opening sealing groove therein, a unitaryseal carried by said outer ringmember cooperating with said ring membersto define one end of a sealed grease chamber between said ring members,said seal comprising an annular outer rubber-like elastic body having anannular metallic ring core forming a relatively rigid reinforcing coreembedded therein with the elastic body in wholly covering relation tosaid metallic ring, said elastic body including a bead-like formationalong the outer edge thereof tightly seated in said stop groove and aforked inner edge formation including a t radially inwardly projectinglip portion and -an axially projecting tongue portion, said lip portionhaving an inwardly convergent, substantially triangular cross sectionproviding an annular planar surface lying perpendicular to the axis ofsaid ring members and facing the center of the grease chamber and aninclined annular surface lying in a conical path converging toward saidaxis and the adjacent end of said ring members, saidsealing grooveconforming substantially to the cross-section of said lip portion `andsaid lip portion extending into the same out of contact with the surfacethereof to form a labyrinth passage therewith, said tongue portion beingof triangular cross-section having a radially inner cylindrical surfacedisposed in spaced concentric overlying relation to an annular portionof said cylindrical outer surface of said inner ring member VimmediatelyVadjoining said sealing groove inwardly of said grease chamber and aradially outer frusto-conical surface converging inwardly of smd greasechamber to a juncture with said inner cylindrical surface, and said sealbeing constructed to maintain said lip portion Iand said tongue portionin slightly spaced relation to said sealing groove surfaces and theadjacent annular surface portions of said inner ring member over thelrange of fluid pressures encountered in said bearing assembly duringuse.

3. In an anti-friction bearing assembly including spaced relativelyrotatable inner and outer race ring members disposed in concentricrelation and held against relative axial movement, `said outer ringmember having a radially inwardly opening stopt groove adjacent one endthereof which -is of substantially triangular cross-section providing anannular planiform stop shoulder lying perpendicular to the axis of thering members spaced from said one end forming a side Wall of the groovejoined by a frustoconical surface forming a base wall of 4the grooveconverging toward said axis to said one end, said inner ring including acylindrical outer surface having an annular outwardly opening sealinggroove therein, a unitary seal carried by said outer ring membercooperating with said ring members to define one end of a sealed greasechamber between said ring members, said seal comprising an annular outerrubber-like elastic body having Ian annular metallic ring core lforminga relatively rigid reinforcing core embedded therein with the elasticVbody in wholly covering relation to said metallic ring,

said elastic `body, including a bead-like formation along the outeredge'thereof tightly seated in said stop groove having ain annularplanar sur-face portion abutting said stop shoulder, said elastic bodyfurther including a forked inner edge formation including a radiallyinwardly projecting lip portion and an axially projecting tongueportion, said lip portion having an inwardly convergent, substantiallytriangular cross section providing an annular planar surface lyingperpendicular to the `axis of said ring members and facing the center ofthe grease chamber and an inclined annular surface lying in la conicalpath converging toward said axis and the adjacent end of said ringmembers, said sealing groove Vconforming substantially to thecrosssection of said lip portion and said lip pontion extending into thesame out of contact with the surface thereof to form a labyrinth passagetherewith, said tongue portion being of triangularA crosssection havinga radially -inner cylindrical surface` disposed in spaced concentricoverlying relation to an annular portion of said cylindrical outersurface of said inner ring membery immediately adjoining said sealinggroove inwardly of said grease chamber and 4a radially outerfrusto-conical surface converging inwardly of said grease chamber to ajuncture with said ,inner cylindrical surface, and said seal beingconstructed to maintain said lip por- Vtion and said tongue portion inslightly spaced relation to of uid pressures encountered in said bearingassembly during use.

4. The combination recited in claim 3 wherein said metallic ring core isprovided with a ange along the References Cited in the le of this patentradially inner edge -thereof inclined along a frustoconical UNITEDSTATES PATENTS path itoward the center of the grease chamber forlimiting deection of said lip portion and tongue portion to pre- 2755113Baumheckel July 17 1956 vent engagement of said portions with theladjacent snr- 5 2759778 Anderson Aug' 21 1956 faces of said inner ringmember. 2856208 Cobb oct' 14 1958 5. The combination reci-ted in `claim4, wherein said FOREIGN PATENTS metallic ring core is provided With `ahook-shaped flange 546,260 Great Britain July 3 1942 along the outerperiphery thereof with said bead-like formation projecting beyond saidhook-shaped flange. 10

1. IN AN ANTI-FRICTION BEARING ASSEMBLY INCLUDING SPACED RELATIVELYROTATABLE INNER AND OUTER RACE RING MEMBERS DISPOSED IN CONCENTRICRELATION AND HELD AGAINST RELATIVE AXIAL MOVEMENT, SAID INNER RINGMEMBER HAVING A CYLINDRICAL OUTER SURFACE HAVING AN ANNULAR OUTWARDLYOPENING SEALING GROOVE THEREIN, A UNITARY SEAL CARRIED BY SAID OUTERRING MEMBER COOPERATING WITH SAID RING MEMBERS TO DEFINE ONE END OF ASEALED GREASE CHAMBER BETWEEN SAID RING MEMBERS, SAID SEAL COMPRISING ANOUTER RUBBER-LIKE ELASTIC BODY HAVING A RIGID METALLIC REINFORCING RINGEMBEDDED THEREIN WITH THE ELASTIC BODY IN WHOLLY COVERING RELATION TOSAID METALLIC RING, SAID ELASTIC BODY HAVING A FORKED INNER EDGEFORMATION INCLUDING A RADIALLY INWARDLY PROJECTING LIP PORTION AND ANAXIALLY PROJECTING TONGUE PORTION, SAID LIP PORTION CONFORMINGSUBSTANTIALLY TO THE CROSS-SECTION OF SAID SEALING GROOVE AND EXTENDINGINTO THE SAME OUT OF CONTACT WITH THE SURFACE THEREOF TO FORM ALABYRINTH PASSAGE THEREWITH, SAID TONGUE PORTION BEING DISPOSED INSPACED CONCENTRIC OVERLYING RELATION TO AN ANNULAR PORTION OF SAIDCYLINDRICAL OUTER SURFACE OF SAID INNER RING MEMBER IMMEDIATELYADJOINING SAID SEALING GROOVE INWARDLY OF SAID GREASE CHAMBER, AND SAIDSEAL BEING CONSTRUCTED TO MAINTAIN SAID LIP PORTION AND SAID TONGUEPORTION IN SLIGHTLY SPACED RELATION TO SAID SEALING GROOVE SURFACES ANDTHE ADJACENT ANNULAR SURFACE PORTIONS OF SAID INNER RING MEMBER OVER THERANGE OF FLUID PRESSURES ENCOUNTERED IN SAID BEARING ASSEMBLY DURINGUSE.